The present invention relates to a pneumatic vehicle tire of belted radial carcass construction with tire beads that are turned axially inwardly and radially outwardly, with each tire bead having a bead core ring that is resistant to compression and bending, with ends of the carcass being anchored about the bead core rings, and with each bead core ring being surrounded by a sheathing made of a vulcanizable elastomeric mixture that cannot fuse with rubber of the carcass and/or rubber of the tire beads.
A pneumatic vehicle tire of this general type is disclosed in German application 38 08 278. In this known tire, each bead core is formed of metal wires and is resistant to compression and bending, with the bead core having a sheathing that is made of a material, for example a rubber mixture, that has a Shore A hardness of greater than 70.degree. and has a relatively smooth surface.
With a pneumatic vehicle tire having tire beads that are turned inwardly, it is necessary during mounting of such a tire on a wheel rim that is specially designed therefor, that the bead cores along with their sheathings be able to advantageously turn relative to the surrounding rubber of the tire bead and of the carcass. This necessitates mixtures that do not fuse with the surrounding rubber.
Such known mixtures comprise rubber mixtures on a basis of butyl rubber or chloroprene rubber. However, these rubber mixtures do not have a great enough adhesion to steel elements of a tire component that is stressed as greatly as is the bead core ring of a pneumatic vehicle tire. In addition, known mixtures that exhibit a better adhesion to steel elements also fuse very well with the surrounding rubber of the bead. It is furthermore known to improve the ability of the bead core ring to turn by producing it as a finished part that is dusted with zinc stearate, or that is sprayed with lubricant. Unfortunately, these measures pollute the environment and must be avoided. It is desirable to improve the ability of the bead core rings to turn without having to use the heretofore known auxiliary measures.
It is therefore an object of the present invention to provide a rubber or elastomeric mixture that adheres well to steel and provides a sufficiently rigid and hard bead core ring sheathing, and that does not fuse with the rubber of the carcass and/or of the bead, but rather as a mixture itself ensures a high ability to turn.